First, check what went wrong
Measure the scale-check bar on your printout with a real ruler or a bank card (85.6 mm wide). Then compare:
| 5 cm bar measures | Likely cause |
|---|---|
| 5.0 cm | Correct, nothing to fix |
| 4.7–4.9 cm | "Fit to page" or "Fit to printable area" is on (shrinks 2–6%) |
| About 4.3 cm | Printed an A4 PDF on Letter paper with fit on, or the reverse |
| Half size or two pages per sheet | "Pages per sheet" or booklet mode is on |
Google Chrome and Microsoft Edge (Windows, Mac, ChromeOS)
- Press Print (Ctrl/Cmd + P) and open More settings.
- Set Paper size to the paper in your printer (Letter or A4).
- Set Scale to Custom and type 100. Do not use "Fit to printable area".
- Set Margins to None or Default. The ruler sheets already keep a safe margin.
Mozilla Firefox
- In the print preview, find Scale and choose 100%.
- Uncheck Fit to page width, which is on by default.
Safari and Preview on Mac
- Press Cmd + P and click Show Details if the dialog is small.
- Set Scale to 100%. In Preview, choose Scale: 100% instead of "Scale to Fit".
iPhone and iPad
Tap Save PDF on the ruler page, open the file, tap the share icon and choose Print. AirPrint prints PDFs at their real size on matching paper, so make sure the printer has the same paper size you chose (Letter or A4). If your printer app shows a "Fit" or "Scale" option, set it to 100% or actual size.
Android
Download the PDF and open it in Google Drive or your PDF app, then use Print. In the print options, set the paper size to match your printer. If you see "Fit to page", turn it off. Some manufacturer print services (HP, Canon, Epson) have their own Scaling setting, so set it to 100%.
Adobe Acrobat Reader
- Open the PDF and press Print.
- Under Page Sizing & Handling, choose Actual size (not "Fit" or "Shrink oversized pages").
- Make sure "Choose paper source by PDF page size" is ticked if your printer has both Letter and A4 trays.
Still a little off?
- Printer driver scaling. Some printer drivers (and copy shops) have their own "Reduce/Enlarge" or "Fit to paper" setting under Preferences or Properties. Set it to 100%.
- Wrong paper size. Printing an A4 layout on Letter paper, or the reverse, can trigger automatic scaling. Pick the paper size that is actually loaded.
- Inkjet paper stretch. Plain paper can expand slightly with heavy ink. Use black and white mode and let the sheet dry flat.
Frequently asked questions
Why does "Fit to page" shrink the ruler?
Printers cannot print to the very edge of the paper, so "fit" options shrink the whole page to fit inside the printable area. On a ruler that makes every mark 2–6% too close together.
Should I print from the browser or the PDF?
Either works if the scale is 100%. The PDF is the safer choice on phones, at copy shops and on shared printers, because it carries its exact page size and asks the viewer not to scale it.
Last reviewed 2026-10-07.